diff --git a/db/db_impl/db_impl_open.cc b/db/db_impl/db_impl_open.cc
index 510fb189b..94f36e862 100644
--- a/db/db_impl/db_impl_open.cc
+++ b/db/db_impl/db_impl_open.cc
@@ -216,7 +216,7 @@ Status ValidateOptionsByTable(
     const DBOptions& db_opts,
     const std::vector<ColumnFamilyDescriptor>& column_families) {
   Status s;
-  for (auto cf : column_families) {
+  for (auto& cf : column_families) {
     s = ValidateOptions(db_opts, cf.options);
     if (!s.ok()) {
       return s;